Digital electronic products such as mobile phones, digital cameras and palmtops have become necessities of life. However, when these products cannot operate normally due to low battery, it is necessary for these products to be charged as soon as possible in order to resume normal operations. Therefore, the battery life has attracted lots of attentions in using the digital electronic products.
Further, existing mobile power supplies mostly are independently charged, which represents a traditional charging manner inapplicable to simultaneous charging of a plurality of the mobile power supplies, resulting in a very low charging efficiency. Therefore, it is difficult to meet the charging demands especially in the case that a plurality of the mobile power supplies are empty of power. In addition, to charge the digital electronic product at home, a suitable charging cable and a charging plug are required, but it is typically annoying in finding small articles such as the charging cable and the charging plug from a mass of stuff. Moreover, all of the mobile power supply, the charging cable, the charging plug, and so on shall be carried for a trip, and hence not only occupy much space in a bag, but also likely make the bag messy due to the cable, thus the charging cable and the charging plug in the bag become difficult to be found and easy to be forgotten.